This invention relates to a method and apparatus for attaching a pin and box pin to a core portion of tapes for fabricating a slide fastener having a separable end stop.
In a slide fastener provided with a separable end stop, a pin and a box pin are attached to one ends of the tape core portions of two stringers, the box pin is inserted into a box and is thereafter secured within the box, and a slider is pushed down along one stringer until it abuts against the box. With the slider held in this attitude, the pin is inserted into the box by way of the slider, which is then pulled up to interlock the fastener elements, namely the zipper teeth. Conventionally, in attaching the pin and pin box, a stringer tape is held by a gripper, the gripper is moved along a predetermined path, and a pin fitting which will serve as the pin or box pin is held in the path of travel of the tape core portion, whereby the core portion is inserted into the pin fitting. The pin fitting is affixed to the core portion by plastic deformation. Positioning the core portion relative to the pin fitting, namely inserting the core portion by a certain amount, is performed by sensing the gripper position and stopping the gripper when the latter has reached a predetermined position. However, this method necessitates sophisticated equipment in order to position the gripper accurately. Since the tapes are deformable, moreover, the position of the core portion relative to the pin fitting fluctuates despite accurate control of the gripper position. Furthermore, because of a fluctuation in the position of the pin fitting relative to a pin fitting holder for holding the pin fittings, the positional relationship between a pin fitting and the core portion, namely the positional relationship between the pin fitting and the fastener elements, is not always fixed. Hence there is a possibility of producing separable slide fasteners which are defective.